In recent history, the transmission of contagious diseases, particularly those brought about exclusively by the co-mingling of human body fluids, has been of great technological interest. One of the particular problems has been associated with the use and disposal of hypodermic syringes, particularly among healthcare professionals. There have been various devices developed for the destruction of the needles or cannula used in such syringes. Additional devices have been developed for capping of syringes, while fixed needle safety syringes have also been designed, all of which attempt to minimize the likelihood of accidental puncture. The accidental puncture or pricking of a finger, or any other part of the body, after the treatment of a patient with a contagious disease, particularly a deadly contagious disease, results in a high likelihood of transmission of that disease. Various syringes have been developed in the prior art to attempt to minimize the likelihood of accidental puncture after patient treatment.
One such device is described in U.S. Pat. No. 4,973,316 to Dysarz wherein a needle is retracted into the barrel of the syringe after the use thereof. Another such device is described in U.S. Pat. No. 4,921,486 to DeChellis, et al.
Other references describing devices relating to needle retraction in a syringe include U.S. Pat. No. 4,994,034 to Bostich et al., U.S. Pat. No. 4,838,869 to Allard, and U.S. Pat. No. 5,114,410 to Batlle, GB 2 197 792 to Powers et al., WIPO 90/06146 to Nacci et al., and WIPO 90/03196 to Utterberg et al. Additionally, U.S. Pat. No. 5,407,431 to Bostich, et al, describes a safety syringe with an interchangeable needle. While all such devices seek the same goals of preventing accidental puncture and providing user flexibility, considerable room for improvement exists.